Originally Posted by TheFuture
I can't see Tony being the one who creates Ultron, that is, unless, he's done it already.
Tony being involved in Ultron's creation doesn't really fly with the end of IM3. He's already had his paranoid phase of creating as much as he can in anticipation of another disaster happening, and it's a phase he had gotten over by the end of the film.
I'm sure one of Tony's suits will indeed be corrupted; I just don't think Tony himself will be involved in it.
I also think that Tony is at a stage in the MCU where he would be very much aware of the potential dangers of creating such a being. So yeah, I don't think he has the inclination or the arrogance to create Ultron.
I disagree with the last paragraph. You were on to something with IM3. In IM3, it is established that Tony's armors can act remotely as controlled by an AI, without his command. He is not wary of this, moreover, he is startled at night by armor that acts on its own and doesn't respond immediately to commands. His reaction is to remove Pepper from the situation, not to shut anything down.
The only thing the end establishes is that he would not create another suit of armor out of paranoia. If there is a legitimate threat, or any other kind of need for Iron Man to appear... why not automated? After all, he's over that, he has no need to hop in a suit and go and save the day himself. He's very comfortable solving whatever the problem is with just his mind. Very comfortable letting JARVIS handle the details.